Low Versus Standard Pressure Pneumoperitoneum on Shoulder Tip Pain

Primary Objective: The primary objective of this study is to determine the effect of low (10 mm Hg) versus standard pressure (15 mm Hg) pneumoperitoneum on post-operative shoulder pain on post operative day one following laparoscopic gynecologic surgery for benign indication.

Secondary Objective: Secondary outcomes measured will include post-operative shoulder tip pain at 1 and 2 hours, QoR score (Appendix A) on POD 1, incidence of post-operative shoulder tip pain (defined as pain rating above zero) at 1, 2, and POD 1, generalized pain, nausea and bloating at 1 and 2 hours and POD 1, as well as rescue analgesia consumption before discharge and use up to POD1. The investigators will also measure intraoperative time, complication rates, estimated blood loss, surgeon visibility rating and anesthetist satisfaction rating, and time to patient discharge. Additionally, investigators will assess rate of failure to complete the surgery at designated pressure (i.e. request to increase pressure).

This proposed study is a single-center parallel group RCT comparing the use of low (10 mm Hg) versus standard pressure (15 mm Hg) pneumoperitoneum at the time of benign gynecologic laparoscopic surgery. Participants will be selected using a convenience sample from Women's College Hospital operating room list. All potentially eligible patients will be invited to participate in this study by the MIS fellow on the day of surgery up to 2 hours before the scheduled surgery. Study consent will be obtained by the MIS fellow or research assistant after the patient has had sufficient time to consider participation in the study.

The investigators will create a randomization list using a computer-generated allocation sequence in equal ratio with study numbers 1 to 82. A member of the research team who will have no interaction with patients in this study will prepare the low and standard pressure envelopes and label them according to the randomization list. Study participants will be randomized on the day of surgery, and the research nurse will set the insufflation pressure to the pre-randomized pressure identified in the envelope. The surgeon, research team, participants and data analysts will be blinded to treatment group. Patients will receive standardized peri-operative care during their operation.

Post-operative pain, nausea, and medication use will be assessed in the PACU. Patients will also be contacted on POD1 to assess post-operative pain scores, calculate total narcotic consumption and elicit any adverse events.

Primary Endpoints: The primary endpoint is post-operative shoulder tip pain measured on POD 1 following surgery by a self-administered NRS for pain. A NRS is a line measuring from 0-10 that rates pain from none (0) to the worst pain imaginable (10). A NRS for subjective pain assessment is a well-established validated measurement tool that has been shown in numerous studies to provide a clinically useful distribution of responses and a detectable treatment effect [Clivatti et al, 2009].

Secondary Endpoints: Secondary outcome measures will include: (a) NRS scores for shoulder-tip pain at 1 and 2 hours (b) QoR score on POD1, (c) NRS scores for generalized pain at 1 and 2 hours and on POD1 (d) post operative nausea, vomiting, and bloating at 1 and 2 hours and on POD1 (e) narcotic consumption measured as total dose of narcotics in PACU and between discharge and the POD1 phone call (f) surgical time (g) estimated blood loss (h) adverse effects/complication rates in hospital and reported by the POD1 phone call (i) surgeon visibility rating and (j) anesthetist satisfaction rating.

Inclusion criteria

The participant must meet all of the inclusion criteria to eligible for this clinical trial:

• All ages > or = to 18 years old;
• Must be deemed to have capacity to provide informed consent;
• Must sign and date the informed consent form;
• Stated willingness to comply with all study procedures;
• Must be undergoing unilateral or bilateral salpingo-oopherectomy or salpingectomy or ovarian cystectomy;

Exclusion criteria

An individual who meets any of the following criteria will be excluded from participation in this clinical trial:

• Previous midline laparotomy;
• Gynecological cancer beyond stage 1 disease;
• Chronic pain;
• Known diagnosis of endometriosis or evidence of endometriosis intra-operatively;
• Fibromyalgia;
• BMI >50;
• Language barrier;
• Inability to communicate or provide informed consent;